• 한국분말재료학회지
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• 제26권4호
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• pp.319-326
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• 2019

Additive manufacturing (AM) is a highly innovative method for joining dissimilar materials for industrial applications. In the present work, AM of STS630 and Ti-6Al-4V powder alloys on medium entropy alloys (MEAs) NiCrCo and NiCrCoMn is studied. The STS630 and Ti64 powders are deposited on the MEAs. Joint delamination and cracks are observed after the deposition of Ti64 on the MEAs, whereas the deposition of STS630 on the MEAs is successful, without any cracks and joint delamination. The microstructure around the fusion zone interface is characterized by scanning electron microscopy and X-ray diffraction. Intermetallic compounds are formed at the interfacial regions of MEA-Ti64 samples. In addition, Vicker's hardness value increased dramatically at the joint interface between MEAs and Ti-6Al-4V compared to that between MEAs and STS630. This result is attributed to the brittle nature of the joint, which can lead to a decrease in the joint strength.

• 한국의류학회지
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• 제13권2호
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• pp.137-145
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• 1989

The purpose of this study was to investigate the effect of the permenent pleats finish on the cystine contents and the physical properties of wool fabrics. Monoethanolamine Sulfite (MEAS) was used as a reducing agent. Cystine contents of the fabrics were determined after the fabric was treated with various MEAS concentrations and steamset time. The cystine contents were increase as the MEAS concentrations were increased. The cystine contents were also increased with steamset time. As the settability showed close relationship with the cystine contents, breakdown and rebuilding of the cystine linkage was thought to play an important role for the settability. Physical properties such as shrink resistance, crease recovery angle and tensile strength were increased as the MEAS concentration was increased. As the stramset time was increased, shrink resistance and crease recovery angle were in creased.

• 한국의류학회지
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• 제13권4호
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• pp.380-387
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• 1989

The Purpose of this study was to investigate the color changes of acid dyed wool fabrics after imparting permanent pleats with si-ro-set finish. Monoethanolamine sulfite was used as a reducing agent. Color changes were determined by measuring CIELAB values after treating the dyed fabrics with various setting temperatures, times and concentrations of MEAS. Setting temperature affected the color changes: in the order of $150^{\circ}C>130^{\circ}C>170^{\circ}C$ Setting time had a tendency to increase the color change. As the concentration of MEAS increased, $\delta$ E was increased. Azo dye was more affected than anthraquinone dye by MEAS treatment. Color changes were mainly due to $\delta$ L.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.398-404
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• 2010

Process conditions for MEA fabrications have significant effects on properties and performance of the MEAs for PEMFCs. In this study, effects of additives on the surface properties of the MEA was investigated to improve homogeneity of the coated catalyst layer. Another parameter that affects on characteristics of the MEAs is hot-pressing condition. Hot pressing condition was optimized by using DOE (design of experiment) method.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.558-563
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• 2014

고분자 전해질 연료전지의 성능과 내구성에 미치는 막 전극 접합체(MEA) 제조방법의 영향에 대해 연구하기 위해 닥터 블레이드 방법, 스프레이 방법, 스크린 프린트 방법 그리고 스크린 프린트+스프레이 방법에 의해 MEA를 제조하였다. 제조된 MEA를 체결한 단위전지의 성능을 측정해 각 MEA의 초기 성능을 비교하였다. 10초간 0.6V 일정전압 유지 후 0.9 V에서 10초간 유지하는 전극 열화 가속 시험(AST)을 각 MEA 적용해 내구성을 시험하였다. 전극 열화 가속 시험 6,000 사이클 전 후 I-V 곡선, 임피던스, 순환 전압측정법(CV), 선형쓸음 전기량측정법(LSV), 투과전자현미경(TEM) 등을 측정하였다. 닥터 블레이드 방법에 의해 제조한 MEA의 초기 성능이 제일 높았고, 스크린 프린트+스프레이 방법에 의해 제조한 MEA가 제일 낮은 열화 속도를 보였다.

• Advances in Traditional Medicine
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• 제8권2호
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• pp.196-203
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• 2008

The methanol extract of the root of Artanema sesamoides Family Scrophuilariaceae (MEAS) was investigated for possible analgesic and anti-inflammatory effects in animals. Three models were used to study the extract effects on nociception, which were acetic acid-induced writhing response, hot-plate method and the tail flick test in mice. The antiinflammatory effects were evaluated using carrageenan, dextran, histamine and serotonin induced rat paw oedema (acute) and cotton pellet induced granuloma (chronic) models in rats. Results of the study revealed that the extract exhibited significant (P < 0.001) analgesic effect at a dose of 50, 100 and 200 mg/kg b.w p.o in mice in all the models. In acute model, the MEAS also exhibited significant (P < 0.001) antiinflammatory effect in all the above mentioned doses. In chronic model (cotton pellet induced granuloma) the MEAS 200 mg/kg and indomethacin 10 mg/kg showed that inhibition of granuloma formation 25.0% and 47.7% respectively (P < 0.001). The MEAS and indomethacin were effectively preventing the transudation of the fluid. Thus, the present study revealed that the methanol extract of the root of Artanema sesamoides exhibited significant analgesic and antiinflammatory activity.

• 무역상무연구
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• 제12권
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• pp.615-641
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• 1999

Trade and the environment emerged as a major and complex issue for trade negotiators in the final stages of the Uruguay Round negotiations. The agreements and other international measures employing trade measures and trade sanctions for achieving global environmental objectives are Vienna Convention on the Protection of the Ozone Layer(1985), the Montreal Protocol on Substances that deplete the Ozone Layer(1987), The Framework Convention on Climate Change(1992), the Convention on Biological Diversity(1992), the Basel Convention on the Control of Transboundary Movement of Hazardous Waste and their Disposal(1992), the Convention on International Trade in Endangered Species of Wild Faunna and Flora(1975), the Rio Declaration, the Agenda 21, etc. The texts of the World Trade Organization(WTO) incorporated certain provisions which were designed to reflect some of the environmental concerns are Trade-Related Aspects of Intellectual Properity Rights(TRIPs), Trade-Related Investment Measures (TRIMs), the General Agreement on Trade in Services(GATS), and Technical Barriers to Trade(TBT) There is the possibility of conflict between multilateral environmental agreements and WTO agreements granting waivers against trade measures and sanctions. This remains a possibility, especially between countries which are Member of WTO and which are not Members of the relevant multilateral environment agreements, and countries which are Members of both the WTO and the relevant MEAs. Measures taken under the trade-related provisions of MEAs could potentially give rise to conflicts under obligations arising in WTO texts. If the parties in dispute are WTO members while they are not members of MEAs, the WTO provisions can be granted a certain priority in terms of international norms and vice versa. When the parties concerned are both WTO members and MEAs, it will be rational to grant the WTO provisions a priority. However, such measures should neither constitute a means of arbitrary or unjustifiable discrimination between countries where similar conditions prevail, nor create a disguised restriction on trade. Also any trade measures taken should be necessary to prevent developments in trade from endangering the effectiveness of an MEA and they should be proportional and least trade restrictive.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.95.2-95.2
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• 2011

In order to achieve high performance and low cost for commercial applications, the development of membrane electrode assemblies (MEA), in which the electrochemical reactions actually occur, must be optimized. Expensive platinum is currently used as an electrochemical catalyst due to its high activity. Although various platinum alloys and non-platinum catalysts are under development, their stabilities and catalytic activities, especially in terms of the oxygen reduction (ORR), render them currently unsuitable for practical use. Therefore, it is important to decrease platinum loading by optimizing the catalysts and electrode microstructure. In this study, we prepared several different MEAs (non-uniform Nafion$^{(R)}$ ionomer loading electrode) which have dual catalyst layers to find the optimal Nafion$^{(R)}$ ionomer distribution in the electrodes. We changed Nafion$^{(R)}$ ionomer content in the layers to find the ideal composition of the binder and Pt/C in the electrode. For MEAs with various ionomer contents in the anodes and cathodes, the electrochemical activity (activation overpotential) and the mass transport properties (concentration overpotential) were analyzed and correlated with the single cell performance. The dual catalyst layers MEA showed higher cell performance than uniformly fabricated MEA, especially at the high current density region.

• 전기화학회지
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• 제10권4호
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• pp.295-300
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• 2007

A new characterization method using a porous plug model was proposed to determine the degree of sulfonation (DS) of ionomer binder with respect to the membrane used in membrane-electrode assemblies (MEAs) and to analyze the fraction of proton pathways through ionomer-catalyst combined electrodes in MEAs for polymer electrolyte fuel cells (PEFCs). Sulfonated poly(ether ether ketone) was prepared to use a polymeric electrolyte and laboratory-made SPEEK solution (5wt.%, DMAc based) was added to catalyst slurry to form catalyst layers. In case of the SPEEK-based MEAs in this study, DS of ionomer binder for catalyst layers should be the same or higher than that of the SPEEK membrane used in the MEAs. The porous plug model suggested that most of protons were via the ionomer binder (${\sim}92.5%$) bridging the catalyst surface to the polymeric electrolyte, compared with the pathways through the alternative between the interstitial water on the surface of ionomer binder or catalyst and the ionomer binder (${\sim}7.3%$) and through only the interstitial water on the surface of ionomer or catalyst (${\sim}0.2%$) in the electrode of the MEA comprising of the sulfonated poly(ether ether ketone) membrane and the 5wt.% SPEEK ionomer binder. As a result, it was believed that the majority of proton at both electrodeds moves through ionomer binder until reaching to electrolyte membrane. The porous plug model of the electrodes of MEAs reemphasized the importance of well-optimized structure of ionomer binder and catalyst for fuel cells.

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 학술대회지
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• pp.53-66
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• 2005